Zooming in on single cells – PhD defense Kim de Luca

Each cell in our body carries the same genetic code in its DNA. Yet cells differ immensely in terms of form and function, because they interpret the information in the DNA differently. This allows each cell to specialize in its specific role. Even processes present in almost all cells, like DNA repair, can vary between cells.

Cellular diversity

When investigating cellular processes, it is therefore important to zoom in on individual cells, rather than studying groups of cells together. Interesting differences between cells might otherwise be overlooked, as they stay ‘hidden’ behind the average. This is why De Luca set out to develop methods that are capable of this type of single-cell research. She mainly wanted to learn more about the individual differences in DNA organization, regulation and repair.

During her PhD research, De Luca succeeded in developing a number of such single-cell methods. With these new technologies, scientists can explore how the DNA interacts with specific proteins to gain insight into all kinds of cellular processes. The unprecedented resolution of these techniques offers a much clearer picture of the diversity of cells than previously possible. For this work, De Luca was recognized as a finalist in MIT Technology Review’s 2025 Innovators under 35.

DNA repair cafés

With these new methods in hand, De Luca was able to study DNA repair in great detail. “DNA can get damaged during normal processes taking place in cells, but also by external factors such as UV radiation and chemicals. Luckily cells have several mechanisms to repair this damage,” De Luca explains. This is important, because unrepaired damage can lead to mutations that can cause diseases such as cancer. De Luca found out that each cell repairs damage differently. She also discovered that damaged segments of DNA cluster together, as if they gather in cellular ‘repair cafés’.

Single cancer cells

More insight into the details of DNA repair could benefit patients with cancer in the future. “For example, by understanding how different cancer cells repair DNA, treatments could become more precise, tailored specifically to how an individual’s tumor responds,” says De Luca. To achieve this, researchers must further develop the single-cell methods into practical diagnostic tools to be used by medical professionals.

An exciting, challenging journey

De Luca describes her PhD as intense and unconventional. “It took a long time and many detours,” she says. For her, a scientific highlight was knowing that you are seeing something for the first time, which nobody has seen before. Socially, her colleagues, who have become good friends, were very important to her. “They really make or break the PhD.”

Of course, there are also challenges. One of the major ones in De Luca’s experience is the way academic success is defined. “This is still mainly determined by the impact and number of your publications. But the publishing process is totally broken, and you are dependent on so many factors outside of your control. I found it really difficult to navigate the duality that academic success is not a reflection of my competence as a scientist, but is measured as such,” De Luca says.

Not “just another job”

Her advice to anyone considering to do a PhD? “Think about your reasons for doing a PhD. If it’s simply because it seems like the next logical step or you are not sure what to do next, I would take a step back and consider that. A PhD is not “just another job”, because there is the expectation of an additional gain, the title, in return for your investment. But you can always decide it is not for you, even after starting. This is not a failure by any means. And you can always decide to pursue a PhD later, if you do something else first!”

For De Luca, doing a PhD was, in the end, deeply rewarding, combining moments of excitement with significant challenges. “As such, I am confident in my persistence and resilience to see things through,” she concludes.